In SU(5) GUTs the gauge bosons mediate nucleon decay via the following well-known dimension six operators [1]}, [2]}, [3]}, [4]}, [5]}:
\(\mathcal {L}_6=-\textbf {C}_{6L}^{ijkl}\;\epsilon _{\hat{a}\hat{b}\hat{c}}\,\epsilon _{ab} \,\overline{u_{\hat{a}i}^c}\,\gamma ^\mu \, Q_{\hat{b}aj}\,\overline{e_k^c}\,\gamma _\mu \, Q_{\hat{c}bl}-\textbf {C}_{6R}^{ijkl}\;\epsilon _{\hat{a}\hat{b}\hat{c}}\,\epsilon _{ab}\,\overline{u_{\hat{a}i}^c}\,\gamma ^\mu \, Q_{\hat{b}aj}\,\overline{d_{\hat{c}k}^c}\,\gamma _\mu \, L_{bl}+\text{H.c.}\,,\) 
